Malcolm Turnbull spent Saturday proudly declaring the need to protect a global rules-based system of liberalised trade under great pressure from threats like the "siren song" of populists or "assertive state capitalism in China". The Asia-Pacific Regional conference in Perth showed Turnbull at his sophisticated best as international statesman.

But by the following day, there was no escape from the latest domestic pressure flaying his government alive. This shows Turnbull trapped in the worst of a raw national psychosis about the legitimacy of politicians.

These days Kevin Andrews may only be a disgruntled Liberal backbencher with a permanent grievance against his leader. But this role also allows Andrews to say out loud what many of his colleagues fear. He cited the timing of the spring racing carnival to utter his latest warning to the Prime Minister.

"The horse has bolted," he declared on Sky. Andrews naturally insists he isn't talking about the viability of Turnbull's prime ministership but about the need to respond to community concerns about the dual citizenship fiasco. He is still using the perception of chaos to talk darkly about "inadequate leadership".

Despite the reluctance of the government to give in to a "witch-hunt" and the practical difficulties of an audit of citizenship that can only be determined by the High Court, it's hard to see how Turnbull can withstand this sort of daily assault to do something, anything, to resolve the problem.

Related Quotes

Company Profile

Former Senate president Stephen Parry has gone to ground and everlasting political disgrace in Tasmania but he's left an almighty mess simmering away in Canberra.

Parry's "oops" moment means too many voters believe there are other MPs who, unwittingly or not, have dual citizenship that makes them ineligible to sit in Parliament.

The subsequent fight between Nationals and Liberals over who should get to take Parry's place as Senate president only confirms in the public mind the venality and absurdity of Australian politics at the fag end of 2017.

That makes it impossible for the federal government to get the necessary traction on other issues and achievements to give it momentum to go into a new year.

Once back in Kirribilli House on Sunday, Turnbull held a meeting with New Zealand's new Labour Prime Minister, Jacinda Ardern. The recent fate of the former National government in New Zealand demonstrates good governments with remarkable policy achievements can still lose office due to bizarre circumstances – in this case the ambition of a 72-year-old populist minor party leader Winston Peters forming an alliance with the election "loser".

Turnbull is facing a different but also potentially lethal political shock with far less of a buffer.

The High Court's strict interpretation of the constitutional requirements to be an MP may have overturned the initial legal confidence of the Solicitor-General, the Attorney-General and the Prime Minister. The questions about other MPs since have overturned the confidence of the public that a government with a one-seat majority really has the right to govern.

Constitutional fallout

Any forced byelections in such circumstances would be most unlikely to be the shoo-in expected for Barnaby Joyce in New England on December 2. And even if individual Labor MPs are also affected by the constitutional fallout, the opposition has a whole lot less to lose.

People may feel sorry for politicians like Josh Frydenberg caught up in this fiasco owing to a tragic family history on his mother's side as Hungarian Jews trying to escape the Holocaust. But Turnbull's emotive call for a return to "the land of commonsense" remains untethered from political reality.

Yes, it all seems absurd. Frydenberg dismisses any possibility he holds Hungarian citizenship. But as more doubts emerge about more MPs, community scepticism about all this won't disappear.

Assistant Minister for Immigration Alex Hawke is just the latest target, thanks to a Greek mother. Israel's "right of return" also looms as an obvious potential constitutional pitfall for all Jewish politicians.

"If any member or senator believes they are not in compliance with the constitution then they should have their matter referred to the High Court, as a number of others have done," the Prime Minister argues.

"This is not a country of witch-hunts. We are governed by the rule of law. If any member or senator believes that one of their colleagues is not sitting in the Parliament constitutionally, then they should stand up, make their case and seek to move, secure support for a motion to refer the matter to the High Court mean, that is the only body that can determine these issues, the only body. That's a fact, that's the law."

And this is politics – where facts are subject to interpretation.

Bill Shorten, demonstrating once again that he can outmanoeuvre the government on political tactics, has changed course on what should happen in the wake of the Parry revelation. After also rejecting an audit, Labor now favours some sort of universal disclosure process undertaken on a bipartisan basis.

How such a process could work is, of course, left deliberately vague. It still means Shorten can accuse the government of having "no plan to resolve the citizenship crisis" while suggesting it is possible to deliver this through better leadership.

The Opposition Leader will continue to use this attack to draw attention to the rampant confusion – and internal sniping – about politicians' citizenship. He will try to feed suspicion this is all about Turnbull's own job protection scheme rather than stability.

Next stop for Turnbull is Vietnam for the Asia-Pacific Economic Co-operation leaders' meeting at the end of this week. It will be a long few days of nasty domestic drama before he gets to play international statesman again.